Permitted 802.11b transmitter power
Posted on 2004-08-03
Hi, I wonder if anyone can help ?
I am currently using a Cisco Aironet 1200 AP with the standard rubber duck aerials.
As I understand it, these dipoles have a gain of 2.2dBi. In the UK we are limited by ETSI regulations in this band to a maximum EIRP of 100mW (20 dBm), which means the AP tx power has to be set to 50mW (17 dBm), which gives an EIRP of 19.2 dBm = 83mW
I need to extend the coverage slightly and was wondering about using a higher gain aerial on the AP. However since I would then have to lower the tx power to 30mW to avoid going over the 20dBm limit, it might not give any improvement. Has anyone any suggestions, and my question is: since the actual received power right next to the AP (measured using a Fluke Waverunner) is only about -30 dBm, why is the permitted EIRP set so low as it seems that most of the tx power is not radiated anyway ?